Accordingly, computer has already penetrated into each family and enterprise to become an indispensable electronic product in our modern lives. Following the prevalence of computer multi-media, more accessory products are needed as the input and output devices, wherein the scanner further becomes one important input device for computer and is also an indispensable accessory device for computer in the application fields of image procession and word data input, such that the scanner is applied in various fields extremely extensively.
Currently, when an optical scanner used for ordinary document is scanning a book of plural pages, the user, in order to consider the fastness and convenience, mostly puts the book pages on the scanning window glass to proceed the scanning job. Usually, the user roughly aligns the book to the surface of the supporting glass by hand together with eye-viewing manner, then starts the scanner to scan so, although it is faster, the page to be scanned will not exactly be within the scanning zone on the supporting glass. Not only so, most pages of the book usually have certain degree of inclination or distortion, such that there are always some errors happened between the original manuscript and the image data after being scanned and, sometimes, a repeated scan has to be proceeded for obtaining a more accurate image effectiveness and, not only is the time wasted, but also is the scanning result poor.
Please refer to FIG. 1, which is an illustration for scanning a book of plural pages by an optical scanner according to the prior arts. As shown in FIG. 1, the scanner 1 includes: shell body 10, upper lid 11, and transparent supporting glass 12, etc. When the user is going to scan a book 13 of plural pages, the book 13 may be roughly put on the supporting glass 12 by manual manner, then the scanner is started to scan but, since the user only puts the book 13 roughly on the surface of the supporting glass 12, so there are often errors happened from this kind of human manner operated by hand and, for most of the time, the pages of the book won't be aimed within the scanning range of the supporting glasses and, sometimes, there is some degree of inclination or distortion, such that various shortcomings are caused as described thereinbefore. Therefore, if a device is designed at the scanner for securing and positioning the book, then above various shortcomings may be avoided, even though it is still operated manually.